I've recently purchased a used 2000 206 from a private individual and have noticed something that I didn't during the test drive - there's a high pitched squeaky noise (just like the noise squeaky brakes), at speeds of 20mph and above. I've noticed this only happens when the steering wheel is very slightly left of centre, perhaps only between 1 and 3 degrees to the left. Any more and the noise disappears, any less - either perfectly straight or anywhere to the right - and there's no noise either. Anyone any ideas what this could be before I take it down the local mechanic and have him charge me a hefty amount for his opinion? TIA.